Species

158 Species

Note that here Darwin is also wrestling with the question of genera being real, a
view he never entirely abandoned. In a letter to Asa Gray in 1857, Darwin discusses
his by-now established opinion that there is no clear distinction between varieties
and species, and how there seems under Darwin’s evolutionary views to be no easy
foundation or set of physical criteria to decide when a variety has earned a specific
epithet:

You speak of species not having any material base to rest on; but is this any greater

hardship than deciding what deserves to be called a variety & be designated by a greek

letter. When I was at systematic work, I know I longed to have no other difficulty (great

enough) than deciding whether the form was distinct enough to deserve a name; & not

to be haunted with undefined & unanswerable question whether it was a true species.

What a jump it is from a well marked variety, produced by natural cause, to a species

produced by the separate act of the Hand of God. But I am running on foolishly.—By

the way I met the other day Phillips, the Palaeontologist, & he asked me “how do you

define a species?”—I answered “I cannot” Whereupon he said “at last I have found out

the only true definition,—‘any form which has ever had a specific name’! ...^20

This anecdote found its way into later mythology in Poulton’s essay on the spe-
cies “problem,”^21 although he dates it a week after the Origin. After the Origin was
published, Darwin had sought Henslow’s reaction:

If you are in even so slight a degree staggered (which I hardly expect) on the immu-

tability of species, then I am convinced with further reflection you will become more

and more staggered, for this has been the process through which my mind has gone.^22

Henslow was sufficiently staggered. He shortly afterward wondered at Owen’s
savage reaction to the views of the Origin:

... when his own are to a certain extent of the same character. If I understand him,

he thinks the “Becoming” of species (I suppose he means the producing of species)

a somewhat rapid and not a slow process—but he seems to think them progressive

organised [sic] out of previously organized beings {analogous (?) to minerals (simple

and compound) out of ± 60 Elements}. (5 May 1860)

And when Sedgwick attacked Darwin in an address, Henslow defended him
actively and forthrightly, also saying in his lectures to students, he reported,

... how frequently Naturalists were at fault in regarding as species, forms which had

(in some cases) been shown to be varieties, and how legitimately Darwin had deduced

his inferences from positive experiment. [Letter 10 May 1860 to Hooker, which was

then passed on to Darwin.]

(^20) 29 November 1857 [Burkhardt 1996, 183].
(^21) Poulton 1903, 1908.
(^22) 11 November 1859. All quotations from Darwin’s correspondence with Henslow are taken from
Barlow 1967.